Effects of Freezing Temperature Parameterization on Simulated Sea‐Ice Thickness Validated by MOSAiC Observations

• Published in: Geophysical Research Letters
• Main Authors: Fengguan Gu, Frank Kauker, Qinghua Yang, Bo Han, Yongjie Fang, Changwei Liu
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2024
• Subjects: Arctic sea ice; freezing temperature; MOSAiC; oceanic heat flux; sea‐ice thickness; parameterization; Geophysics. Cosmic physics; QC801-809; Arctic; Sea ice
• Online Access: https://doi.org/10.1029/2024GL108281; https://doaj.org/article/0175dca28c4d4f50ba036ae743c77137

Abstract Freezing temperature parameterization significantly impacts the heat balance at sea‐ice bottom and, consequently, the simulated sea‐ice thickness. Here, the single‐column model ICEPACK was used to investigate the impact of the freezing temperature parameterization on the simulated sea‐ice thermodynamic growth during the MOSAiC expedition from October 2019 to September 2020. It is shown that large model errors exist with the standard parameterization and that different formulations for calculating the freezing temperature impact the simulated sea‐ice thickness significantly. Considering the winter mixed layer temperature, a modified parameterization of the freezing point temperature based on Mushy scheme was developed. The mean absolute error (ratio) of simulating sea‐ice thickness for all buoys reduces from 7.4 cm (4.9%) with the “Millero” scheme, which performs the best among the existing schemes in the ICEPACK model, to 4.2 cm (2.9%) with the new developed scheme.